Ethylenically unsaturated olefins without heteroatom substitution typically have low copolymerization rates with polar monomers such as acrylates. The copolymerization technology of olefins with polar monomers is reviewed in WO 03/070783 and WO 2005/054305 both owned by PPG Industries Ohio, Inc. The olefins are described as electron donating type monomers and the acrylates are described as electron accepting monomers. Styrene copolymerization with maleic anhydride is discussed in WO 03/070783 in paragraph [0002] and described as forming charge transfer complexes and resulting in some alternating sequences. Styrene is a somewhat nonpolar monomer that does readily copolymerize with acrylates and other polar monomers by free-radical mechanisms even in the absence of charge complexation. While styrene does contribute to a more hydrophobic acrylate polymer, the resulting polymers have high glass transition temperature(s) and are not useful for many applications where soft-flexible film formation is desired.
In WO 03/070783, Examples A and B of the copolymers they feed 3 or 4 different charges into a reaction vessel over several hours maintaining a temperature of 140-160° C. and pressures from 5 psi to 62 psi in Example A and 40 to 360 psi in Example B. Molecular weights were number averages of 2293 and 4274 while the weight averages were 8317 and 12,856 gram/mole. These copolymers were blended with more conventional latexes and made into curable film forming compositions.
In WO 2005/054305, Examples 1-4 were 25/20/55 w/w/w/ of isobutylene/hydroxypropyl acrylate/butyl acrylate polymerized into a copolymer by the method of the patent application. The monomers and di-t-amyl peroxide were prepared in three separate feed tanks and commingled in a feed line just prior to addition to the 5-gallon stirred reactor. The reactor was maintained between 200 and 210° C., at a pressure of 500 psi for a residence time of 16 to 25 minutes. The resulting polymer was reported to have a composition of 21 wt. % isobutylene, 27 wt. % hydroxypropyl acrylate, and 52 wt. % butyl acrylate. The copolymer was reported to have number average molecular weights between 1446 and 1699 and weight average molecular weights between 2781 and 3441 g/mole.
U.S. Pat. No. 4,820,762 is an early patent on Resin-Fortified Emulsion Polymers and Methods of Preparing the Same. The abstract expresses: The stability and physical properties of high molecular weight emulsion polymers are improved by the addition of a low molecular weight support resin during the emulsion polymerization process. The resin is soluble or dispersible in water or alkali and has a number average molecular weight between 500 and 20,000.
U.S. Pat. No. 6,020,061 is a later patent on Emulsion Polymerization Using Polymeric Surfactants. The abstract expresses: An emulsion polymerization system comprising a polymeric stabilizer, wherein the polymeric stabilizer comprises one or more alpha olefin/maleic anhydride copolymers and is present in the emulsion polymerization system in an amount greater than 0 and less than 5% by weight.
It would be desirable to copolymerize ethylenically unsaturated olefins of 4 to 30 carbon atoms with polar monomers such as acrylate monomers in large commercial reactors in aqueous media at 1 or 2 atmosphere pressure. It is also desired to make polymers over 50,000 molecular weight, preferably over 100,000 molecular weight to obtain optimum desired properties. It would be desirable to have hydrophobic olefins that copolymerize with acrylates and other polar co-monomers to form moderate to low glass transition temperature polymers for use in many ink, adhesive, and coating applications.